Albert c



A. c. DJEHL. SOUND 'BOX FOR SOUND REPRODUCING AND SOUND RECORDING MACHINES.

APPLICATION FILED SEPT. 14, 1915. RENEWED JAN-17,1920- 'Patented Aug. 24, 1920..

tll illlll ll lpl umywij EVITNESSES ATTORNEYS UNITED STATES PATENT QFFICE.

ALBERT C. DIEHL, OF PENSAUKEN, NEW JERSEY, ASSIGNGR VICTOR TALKING MACHINE COMPANY, A CORPORATIDN OF NEW JERSEY.

' SOUND-BOX FOR SOUND-REPRODUCING AND SOUND-RECORDING MACHINES.

Application filed September 14, 1915, Serial No. 50,551;

sound reproducing and sound recording machines and particularly to the supporting mechanism upon which the stylus bar is mounted to oscillate in transmitting vibra tions to and from the diaphragm through the stylus bar, and my invention has for its objects, among others, to provide a construction in which the stylus bar may be put under tension and in which the degree to which such tension is applied may be adjusted, regulated and controlled to a 'nicety and accuracy heretofore unattained, without substantially increasingthe frictional resistance to the free vibration ofthe'stylus bar; to prevent the'compression or tension memher from. vibrating independently of its vibration by andwith the stylus bar about theoscillatory axis of the stylus bar; to so arrange the compression or tension member that its mass is disposed substantially equal on opposite sides of the axis of oscillation of the stylus bar and thus position'it in a balanced relation with respect to the axis of oscillation of the stylus bar to improve the quality of the sound reproduced and to more truly recordsound by avoiding any liability of chatteror vibration in the parts of the sound box construction; and to. perunit the stylus bar to move with the least restraint possible in recording or reproducingsound.

.Other objects of my invention are to simplify and reduce the weight of 'theelementa'l parts of the sound box, particularly of the stylus bar mounting and to avoid any varia: tions in'resistance to the swinging or oscillatory movement of the stylus bar.

Other objects of 'my invention will appear in the specification and claims below.

"To these ends my invention consists generally of the combination of elements, and

lso of the specific construction of some of the elements in lesser combination of them,

Specification of Letters Patent.

Patented Aug. 24, 1920.

Renewed January 17, 1920. Serial No. 352,232.

as hereinafter descril'i d and pointed out in the appended claims.

Referring now to the drawings forming a part of this application, and in which the same reference characters are used to designate the same parts throughout the various views, Figure 1 is a side elevational view, partly in section, of a sound box having a stylus mounted in accordance with the invention of this application;

Fig. 2 is a front elevational view of the construction shown in Fig. 1;

Fig. 3 is a bottom view of the construction shown in Fig. 1;

Fig. 4 is an enlarged longitudinal sectional view ofa portion of the stylus bar and a longitudinal view of the mounting therefor. said section being taken on the line 4.4 in Fig. 3; A

Fig. 5 is a longitudinal sectional view enlarged similarly to Fig. 4, of a portion of the stylus bar and the mounting therefor, said section being taken on line 5-.-5 of Fig.2.

Fig. 6 is a further detailed view showing the surface on the end of the adjustable screw stud andthe surface at the bottom of the recess in the resilient member as having radii of curvatures greater than the showing a modified construction .in which the bottom ofthe recess in the springinemher is conical in shape as'distinguished from spheucal. 1

Referring first to the form of the invention asillustrated in Figs. 1 to 10 of the drawings, there is provided a support 1 rigidly secured in' any manner, as by screws 22,-to the outer surface of a sound box casing 3 within which is mounted in any approved manner the usual vc'liaphragm 4. This support is preferably formed so as to provide two blocks or lugs 55 disposed symmetrically with respect to a plane passing through the center of the diaphragm. Near the outer and free ends of said blocks iii) or lugs 5 are provided a pair of alined screw studs 6G, each threaded through the block or lug in which it is mounted and each provided with a loclr nut 7-7 by means of which said studs -66 may be rigidly locked in place after having beenadjusted to the desired position.

The upper end of the stylus bar 8 is attached to the center of the diaphragm in any approved manner, as, for instance, by the screw 9, and the wax or cement 10 as is common in sound box construction. The stylus bar 8 is provided on its outer end with the usual socket within which be inserted the stylus or needle 11 and is pro vided with the usual set screw 12 for securely clamping the stylus or needle 11 in the stylusbar.

Intermediate the ends of the stylus bar 8 is preferably provided a larger portion or section 13, the outer surface of wh1ch 1s provided with a groove or channel 1 1 which is preferably rectangular in shapetransversely of the groove and cylindrical in shape longitudinally thereof to provide a seat within which a spring, compression or tension member 15, more particularly described below, may be rigidly secured. Upon each side of the channel 14 and formed 7 thereby are the lugs 1 1 14' which clamp the member 15 as later referred to.

The spring, compression or tension member 15 is preferably made substantially annular in shape and rectangular 1n crosssection and said spring member is intransverse cross-section of the size and shape of the channel ltin the larger section 13 of the stylus bar 8. The said member 15 is of integral construction and is preferably made by first forming a steel ring or annulus 16 (as shown in Fig. 8) and then cutting or milling a recess 17' on the inside thereof to form a resilient web or connecting portion 18. The web is then forced and bent inwardly in any suitable manner as by a swaging process to form a resilient web 19, the exterior surface of which, lnstead of being convex is concave. If so desired, the outer surface of the web 19 may be made more concave than the web 18 is convex; that is to say, the radius of curvature of the concave surface of the web 19 of the finished member shown in Fig. 11 may be less than the radius of the curvature of the convex surface of the web 18 prior to the swaging process and as illustrated in Fig. 10. Then so constructed, the whole ring or annulus 16 is preferably slightly reduced in diameter during the swaging process to compensate for the consequent lessening of the distance between the thicker portions of the member on the other sice of the web.

The compression member 15 thus formed is afterward rigidly secured tothe stylus bar preferably by sweatingthe said memher into the groove or channel 14 and be tween the lugs 14c 14: which serve to clamp the member 15 with its relative stiff resilient portions 20-20 symmetrically disposed and arranged to the stylus bar '8 and with respect to the web 19. These resilient portions 2020 are preferably substantially semi-circular in shape longitudinally con sidered. 7

Either before or after the compression member 15 has been thus secured tothe stylus bar, it is provided on the opposite sides thereof with alined recesses 2121, the line between said recesses preferably intersecting the aXis on the stylus bar at that point. In the embodiment of the invention illustrated in Figs. 1 to 10, the recesses 21 are provided with spherical surfaces 22, the radii of which surfaces are greater than the radius of the ball 23 arranged to be seated therein. The inner end of each stud 6-6 is also preferably provided with a recess 2 the surface of which is preferably spherical and of greater radius than the radius of the ball 23. In each recess 21 of the compression member 15 is provided a ball 23 against which the recessed end at of the cooperating or coacting screw stud 6 is adapted to hear when thedevice is assembled in the manner shown in Figs. 1 t0 4.

By virtue of the fact that the radii of compression member and screw studs are respectively greater than that of the balls 23 interposed between them, theoretically there is buta single point of contact between the ball 23 and its cooperating stud 6, and

between each ball and the compression member 15, and as these points of alinement are substantially coincident with the axes of the alined studs 6-6, the stylus bar oscillates about these points of contact as an axis.

, In the modification shown in Fig. 11, the bottom 22" of the recesses 21 in the compression member 15 are conical, as distinguished from spherical and the stylus bar will oscillate about the points of contact between the studs 6 and the balls 23, but the conical surfaces of the recesses 21 will hold the balls in alinement with the axes of the substantially the same size throughout in curvature of the recesses 21 and 24: in the cross-sectional area, such independent vibra tion of said parts of the compressionmember might be obviated, but the said portions 20-20 would not be relatively freely mov' able toward and away from each other under the compressive action ofthe alined studs 6-6. Thus the relatively free movement ofthe portions 20-20 toward and away from each other for the adjustment of the tension thereon between the alined studs 6-6 would be destroyed. When; how ever, the portions 20-20 are connected together by the thin resilient web 19 integral with said portions, this web does not substantially interfere with or prevent'the controlled relative movement of said parts 20-20 toward and awayfrom each other under the adjustive action of the screws 6-6, but tends to absorb, prevent or control any free or independent vibration of the said parts 20-20- which are of full crosssection, and modifies or affects the flexibility of the said portions 20-20. The construction is such that the compression member has portions having different degrees of re silient flexibility, each of which mutually modifies the flexibility or resiliency'of the other part or parts of the member. The device, therefore,-embodies a construction'in which the tension, to which the resilient compression member is subjected, may delicately be adjusted without the liability of having in the reproduced sound undesirable sounds.

With the parts, arranged, constructed and assembled in the manner above set forth, the spring or compression member 15 encircles the stylus bar and is disposed in aplane substantially normal to the longitudinal axis of the stylus bar at its pointof attachment thereto. The length of the thin resilient web 19 is substantially the same as the length of the groove 14 in the stylus bar in which the resilient member 15 is seated, and the weight of the parts 20-20 of'the resilient member 15 on either side of the axis of oscil lation of the stylus bar is substantially equal with the result, therefore, that the effective portions of the compression member are disposed in a substantially balanced relation with respect to the axis of oscillation of the stylus bar.

With the stylus bar substantially vibrating upon a single point on a spherical surface, it must be obvious that said point of contact is very much more durable and uniform in its action than an ordinary conical pivot point would be; and that the mounting will be substantially free from any cramping or similar action should the studs or screws 6-6 be not exactly in perfeet alinement with each other, although, of course, it mustbe bornein mind that in making the constructions illustrated in the drawings ofthis application the said adjusting screws 6-6 and the recesses in the C(HHPIQSSlOD member arranged to receive the balls are made in as nearly perfect alinement as careful machine'work permits.

This construction also makes it possible to completely obviate the chatter or rattle of the said parts of the stylus mounting during the operation thereof because of the manner in which the surfaces engage and the ability to put the stylus bar under whatever tension may be found necessary or desirable without unduly increasing the resistance to the free oscillation of the stylus bar upon its virtual pivot.

l aving thus described this invention what is claimed and is desired to protect by Letters Patent of the United States is:

1. In a sound box, the combination of a stylus'bar and a transverse resilentloop rigidly secured to said stylus bar, and having portions varying from each other in resilient flexibility.

2. In a sound box, the combination of a stylus bar, a flexible member surrounding said stylus bar and moving therewith, said flexible member having a portion which modifies the flexibility of other portions of said member.

3. In a sound box, the combination of a stylus bar, a flexible member through which said stylus bar passes, disposed in a plane transverse to the longitudinal axis of said stylus bar and having a reduced portion to modify the flexibility of other portions of said flexible member.

1. In a sound box, the combination of a stylus bar, 1 exible member encircling said stylus bar and moving therewith, and pivotal bearings about which said stylus bar and said member are vibratible, said flexible member being extended upon both sides of the pivotal bearings and the weight thereof upon each side of said bearings be ing substantially equal whereby said flexible member in itsoscillation about the pivotal bearings tends to move with balanced motion.

5. In a sound box, the combination of a stylus bar, a continuous flexible member rigidly secured to said stylus bar and extending therearoundand transverse thereto, a bearing for said flexible member about which said flexible member and stylus bar are arranged to vibrate, the axis of vibration of said stylus bar and said flexible member being disposed that portions of both members are upon opposite sides of said axis and at some distance therefrom whereby the movement of the stylus bar and flexible member is a substantially balanced motion due to the disposition of weight of A parts upon both sides of the axis.

6. In a sound box, the combination of a stylus bar and a resilient compression member disposed 1n a plane transverse to the longitudinal axis of said bar, said compression member having a portion reduced in cross-section to provide a resilient member which joins the adjacent portions of the full crosssection portions of said resilient member, whereby said reduced cross-section prevents independent movement of the pertions of full cross-section adjacent thereto.

7. A sound box of the class recited, comprising in combination a casing, a diaphragm, a stylus bar connected thereto and having spaced lugs projecting therefrom, a ring member extending around said stylus bar and clamped thereto between said lugs, and provided with diametrically opposite recesses, bearing balls, one in each of said recesses, respectively, wings or projections extending from said casing to a position adjacent said ring member, and oppositely disposed screw studs mounted in said wings and having cupped ends adapted to engage said bearing balls.

8. In a sound box, the combination with a stylus bar, of a compression member, rigidly secured to and encircling said stylus bar and having a resilient reduced portion, a pair of alined studs adjustable toward and away from each other and arranged to compress said resilient member between them.

1 9. In a sound box, the combination with a stylus bar, of a compression member forming a part of said stylus bar and having resilient portions disposed on opposite sides of said stylus bar, a pair of alined studs adjustable toward and away from each other and arranged to compress said resilient portions between them, each of said resilient portions being provided with a recess in alinement with said studs, and a pair of balls, each seated in one ofsaid recesses respectively and in engagement with the end of one of said studs.

10. In a sound box, the combination with a stylus bar, of a compression member forming a part of said stylus bar and having resilient portions disposed on opposite sides of said stylus bar, a pair 01" alined studs adjustable toward and away from each other and arranged to compress said resilient portions between them, each of said portions being provided with a recess in alinement with said studs, and a pair of balls, each seated in one of said recesses respectively and in engagement with the end of one of said studs, the inner ends of said studs being recessed to provide a spherical surface of a greater radius than the radius of the ball cooperating therewith.

11. In a sound box the combination with a stylus bar, of a compression member secured to saidstylus bar and having resilient members disposed on opposite sides of said stylus bar, a pair of alined studs adjustable toward and away from each other and arranged to compress said resilient members between them and means connecting together the free ends of said resilient members to prevent the independent vibration of said portions.

12. In a sound box, the combination with a stylus bar, of a compression member secured to said stylus bar and having resilient members disposed on opposite sides of said stylus bar and arranged substantially concentric with the longitudinal axis of said stylus bar, of a pair of alined studs arranged to spring said resilient members toward each other and a resilient web connecting together said resilient members.

13. In a sound box, the combination with a stylus bar, compression' member at tached to and forming a part of said stylus bar and having resilient members disposed on opposite sides of said stylus bar and arranged substantially concentric with the longitudinal axis of said stylus bar, of a pair of alined studs arranged to spring'said resilient members toward each other and a resilient web integral with and connecting together said resilient members.

14. In a'sound box, the combination with a stylus bar, of a continuous compression member forming a part of said stylus bar with its plane normal'to the axis of said stylus bar, a pair of alined studs adjustable toward and away from each other, said compression member moving with said stylus bar and exerting its action against said studs with the same degree in all positions, said compression member being formed at one portion thereof with a reduced part extending between two adjacent unreduced parts.

15. In a soundebox, the combination with I .and arranged to compress said compression member between them. a

16. In a sound box, the combination with a stylus bar, of a compression member connected thereto and a pair of alined studs adjustable toward and away from each other and arranged to compress said compression member between them, said compression member being provided with resilient portions disposed practically equally about the axis of said alined studs, said portions serving to balance the parts and the motions thereofdue to the substantially equal distribution of weight of said flexible member about the axis of the alined studs.

-17. A mounting for a stylus bar for sound reproducing machines, comprising a resilient ring adapted to be rigidly attached to and to surrounda stylus bar, and provided with a pairof diametrically oppositely positinned recesses, and with a resilient por tion forming an integral part of said ring, said portion being of considerably reduced cross-sectional area and located between said recesses.

18. A mounting for a stylus bar for sound reproducing machines, comprising a resilient ring adapted to be rigidly attached to and'to surround a stylus bar, and pro vided with a pair of diametrically oppositely positioned surfaces upon which said member is adapted to be supported for vibration, and with a resilient portion forming an integral part of said ring, said por tion being of considerably reduced crosssectional area, and being located between said surfaces.

In witness whereof, I have hereunto affixed my signature this 13th day of September, 1915.

ALBERT C. DIEHL, 

